Solved

explanation of if isnull sql statement

Posted on 2014-03-27
4
272 Views
Last Modified: 2014-03-27
Could somebody clarify what is going on in this statement. The part that I am not sure about is...at the end  ,' ') = ' '

if isnull(@filename_to_import,' ') = ' '

Thanks
0
Comment
Question by:tesla764
  • 2
4 Comments
 
LVL 15

Assisted Solution

by:tim_cs
tim_cs earned 200 total points
ID: 39960022
It's checking to see if @filename_to_import is NULL or an empty string.

ISNULL() checks the first value @filename_to_import, if it is NULL then it returns whatever is in the second half, in this case an empty string.  If it's not NULL then it will return whatever value @filename_to_import is.
0
 
LVL 65

Accepted Solution

by:
Jim Horn earned 300 total points
ID: 39960030
> isnull(@filename_to_import,' ')
Return either the contents of the @filename_to_import variable if it's not NULL, or return a single space ' '.   This approach is useful when you want to weed out NULLs early before doing expressions.

>if isnull(@filename_to_import,' ') = ' '
If the @filename_to_import variable contains either NULL or '', then do whatever is below that line, such as..
if isnull(@filename_to_import,' ') = ' '
   begin
   -- There's no file name to import.  
   -- Either do an alternate thing, or end the sp. 
   end 
ELSE 
   begin
   --  There's a file name to import.  Rock on. 
   end

Open in new window

0
 

Author Closing Comment

by:tesla764
ID: 39960039
Thanks Everybody. That was very helpful.
0
 
LVL 65

Expert Comment

by:Jim Horn
ID: 39960084
Thanks for the split.  Good luck with your project.  -Jim
0

Featured Post

Webinar: Aligning, Automating, Winning

Join Dan Russo, Senior Manager of Operations Intelligence, for an in-depth discussion on how Dealertrack, leading provider of integrated digital solutions for the automotive industry, transformed their DevOps processes to increase collaboration and move with greater velocity.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
find SQL job run average duration 24 57
Convert VBA UDF to SQl SERVER UDF 4 51
Specify timing interval fro change data 2 57
A question about syntax 5 29
In this post we will learn different types of Android Layout and some basics of an Android App.
In this post we will learn how to make Android Gesture Tutorial and give different functionality whenever a user Touch or Scroll android screen.
In this fourth video of the Xpdf series, we discuss and demonstrate the PDFinfo utility, which retrieves the contents of a PDF's Info Dictionary, as well as some other information, including the page count. We show how to isolate the page count in a…

730 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question